(12) United States Patent Armenio et a].

Transcription

1 US B2 (12) United States Patent Armenio et a]. (10) Patent N0.: (45) Date of Patent: Apr. 23, 2013 (54) TWO-SETTINGVARIABLE-ECCENTRICITY VANE PUMP (75) Inventors: Giacomo Armenio, Livorno (IT); Bernardo Celata, Livorno (IT) (73) Assignee: Pierburg Pump Technology Italy S.p.A., Lanciano (IT) ( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 860 days. (21) Appl. No.: 11/997,636 (22) PCT Filed: Aug. 1, 2006 (86) PCT No.: PCT/IB2006/ (0X1) (2), (4) Date: Oct. 15, 2009 (87) PCT Pub. No.: WO2007/ PCT Pub. Date: Feb. 8, 2007 (65) Prior Publication Data US 2010/ A1 Apr. 8, 2010 (30) Foreign Application Priority Data Aug. 2, 2005 (IT)..... TO2005A0543 (51) Int. Cl. F01C 20/18 ( ) F 01C 20/22 ( ) F04C14/18 ( ) F04C 14/22 ( ) (52) U.S. Cl. USPC /29 (58) Field of Classi?cation Search l8/22i27, 418/29, 31 See application?le for complete search history. (56) References Cited DE GB JP U.S. PATENT DOCUMENTS 3,771,921 A * 11/1973 Rohde etal /26 4,035,105 A * 7/1977 Dantlgraber 418/26 4,222,718 A * 9/1980 Lemke /26 (Continued) FOREIGN PATENT DOCUMENTS A1 11/ A 7/ A 9/1982 OTHER PUBLICATIONS Hilbert J.-M., Pompes a palettes autoregulatrices PVS a compensa tion hydraulique des jeux, Energie Fluide, Jan. 1989, pp. 4-8, v01. 28, N0. 1, CFE, Paris, France. International Search Report, PCT/IB2006/002085, Dec. 27, Primary Examiner * Mary A Davis (74) Attorney, Agent, or Firm * Robert P. Lenart, Esq.; Pietragallo Gordon Alfano Bosick & Raspanti, LLP (57) ABSTRACT A variable-eccentricity vane pump having a rotor?tted With blades; an adjusting ring housing the rotor; elastic means for forcing the adjusting ring into a maximum-eccentricity posi tion With respect to the rotor; a?rst sliding member connected to the adjusting ring and Which slides in?uidtight manner inside a?rst chamber connected hydraulically to a delivery conduit of the pump; and a second sliding member connected to the adjusting ring and Which slides in?uidtight manner inside a second chamber connected hydraulically to a deliv ery conduit of the pump. The?rst sliding member is con nected to the adjusting ring on the opposite side to the elastic means and the second sliding member; and the second cham ber is smaller than the?rst chamber, and has a drain opening formed in a lateral Wall on Which the second sliding member slides. 4 Claims, 1 Drawing Sheet

2 Page 2 US. PATENT DOCUMENTS 4,950,137 A * 8/1990 Fischer et a /26 5,236,319 A 8/1993 Fischer et 31. 4,325,215 A * 4/1982 Yarnamoto /27 4,780,069 A * 10/1988 Dantlgraber et a /26 * cited by examiner

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4 1 TWO-SETTING VARIABLE-ECCENTRICITY VANE PUMP CROSS-REFERENCE TO RELATED APPLICATIONS This application is a US. National StageApplication under 35 U.S.C. Section 371 of PCT International Application No. PCT/IB32006/002085,?led Aug. 1, 2006, which is incorpo rated herein by reference as if set forth in its entirety. TECHNICAL FIELD The present invention relates to a two-setting, variable eccentricity vane pump. More speci?cally, the pump accord ing to the present invention provides for pumping lubricating oil to an internal combustion engine, to which speci?c refer ence is made in the following description purely by way of example. BACKGROUND ART As is known, variable-eccentricity vane pumps have only one delivery pressure setting, which means the pump, par ticularly at high speed, supplies oil at pressures higher than those actually required by the engine. To eliminate this drawback, devices have been designed to substantially continuously adjust operation of the pump. Though successful in solving the above problem, such devices employ electronic central control units which make them both expensive and fragile. DISCLOSURE OF INVENTION It is an object of the present invention to provide a pump designed to provide a straightforward, low-cost solution to the problems of the known state of the art. According to the present invention, there is provided a variable-eccentricity vane pump comprising a rotor?tted with blades; an adjusting ring housing said rotor; and elastic means for forcing said adjusting ring into a maximum-eccen tricity position with respect to said rotor; said pump being characterized by comprising a?rst sliding member connected to said adjusting ring and which slides in?uidtight manner inside a?rst chamber connected hydraulically to a delivery conduit of the pump; and a second sliding member connected to said adjusting ring and which slides in?uidtight manner inside a second chamber connected hydraulically to a deliv ery conduit of the pump; said?rst sliding member being connected to said adjusting ring on the opposite side to said elastic means and said second sliding member; and said sec ond chamber being smaller than said?rst chamber, and com prising a drain opening formed in a lateral wall on which said second sliding member slides. BRIEF DESCRIPTION OF THE DRAWING A non-limiting embodiment of the invention will be described by way of example with reference to the accompa nying drawing, which shows a cross section, with parts removed for clarity, of the pump according to the present invention BEST MODE FOR CARRYING OUT THE INVENTION Number 1 in the accompanying drawing indicates as a whole the variable-eccentricity vane pump according to the present invention. Pump 1 comprises, in known manner, a main body 2 having a cavity 3; an adjusting ring 4 housed inside cavity 3, in which it can translate as described below; and a rotor 5?tted with blades (not shown), housed inside adjusting ring 4, and having an axis of rotation?xed with respect to main body 2. As is known, by varying the eccentricity between rotor 5 and adjusting ring 4, the delivery of pump 1 can be regulated as required by a user device (not shown) located downstream from pump 1 and de?ned, in the example shown, by an internal combustion engine. As shown in the drawing, pump 1 comprises a preloaded spring 6 compressed between a wall 711 of a seat 7 formed in main body 2, and a wall 8 de?ned on an outer surface 411 of adjusting ring 4. Positioned as described above, spring 6 forces adjusting ring 4 into a maximum-eccentricity position with respect to rotor 5 and, hence, into a condition in which oil delivery by pump 1 is maximum. As shown in the drawing, pump 1 comprises a?rst chamber 9 and a second chamber 10, both formed in main body 2 and facing each other inside cavity 3. Each chamber 9, 10 is connected to a conduit for feeding oil from pump 1 to the engine. More speci?cally, chamber 10 is connected to an oil tank by a drain opening 11 formed in a lateral wall 10a, and is formed in the same part of main body 2 as seat 7 of spring 6. As shown in the drawing, pump 1 comprises a?rst sliding member 12 and a second sliding member 13, both formed in one piece with adjusting ring 4, and which slide in?uidtight manner inside?rst chamber 9 and second chamber 10 respec tively. More speci?cally, each sliding member 12, 13 has a respective work surface 12a, 1311, on which the pressure of the oil supplied by the pump and present inside respective cham ber 9, 10 exerts a force to move sliding member 12, 13. In actual use, starting with rotor 5 and adjusting ring 4 set to the maximum-eccentricity position by spring 6, the speed of the rotor is increased, thus increasing the pressure of the oil supplied by the pump. The increase in oil pressure produces an increase in pressure in chamber 9, so that force is exerted on surface 12a of sliding member 12. In chamber 10, on the other hand, drain opening 11 prevents the pressure from increasing, so that no force is exerted on sliding member 13. In the above condition, when the force of the pressure on surface 12a exceeds the opposing force of spring 6, adjusting ring 4 is moved in the direction indicated by arrow F, thus reducing the eccentricity with respect to rotor 5. As adjusting ring 4 moves, a position is eventually reached in which sliding member 13 closes drain opening 11. In the above condition, to move adjusting ring 4 further, the pressure in chamber 9 must generate enough force to coun teract not only the force of spring 6 but also the force exerted on surface 1311 by the pressure generated in chamber 10, which is smaller than chamber 9. In chamber 10, in fact, the pressure tends to increase, on account of oil drainage through opening 11 being prevented. In other words, as the pressure of the oil supplied by pump 1 increases, adjusting ring 4 moves in the direction of arrow F according to two different, consecutive laws. That is, the movement of adjusting ring 4 is?rst opposed solely by spring 6, and then also by the force exerted on surface 1311 by the oil pressure in chamber 10.

5 3 The pump according to the present invention provides for achieving oil supply as close as possible to the actual demand of the engine, and, at the same time, unlike known solutions, is extremely straightforward and cheap to produce. The invention claimed is: 1. A variable-eccentricity vane pump (1) comprising a rotor (5)?tted With blades; an adjusting ring (4) housing said rotor (5); and elastic means (6) for forcing said adjusting ring (4) into a maximum-eccentricity position With respect to said rotor (5); said pump being characterized by comprising a?rst sliding member (12) connected to said adjusting ring (4) and Which slides in?uidtight manner inside a?rst chamber (9) connected hydraulically to a delivery conduit of the pump; and a second sliding member (13) connected to said adjusting ring (4) and Which slides in?uidtight manner inside a second chamber (10) connected hydraulically to a delivery conduit of the pump; said?rst sliding member (12) being connected to said adjusting ring (4) on the opposite side to said elastic 4 means (6) and said second sliding member (13); and said second chamber (10) being smaller than said?rst chamber (9), and comprising a drain opening (11) formed in a lateral Wall (1011) on Which said second sliding member (13) slides. 2. A pump as claimed in claim 1, characterized in that said?rst sliding member (12) and said second sliding member (13) are formed in one piece With said adjusting ring (4). 3. A pump as claimed in claim 1, characterized by com prising a main body (2), in Which are formed a cavity (3) housing said adjusting ring (4), and said?rst (9) and second (10) chamber facing each other inside said cavity (3). 4. A pump as claimed in claim 3, characterized in that said elastic means comprise a preloaded spring (6) compressed between a Wall (711) of a seat (7) formed in said main body (2), and a Wall (8) de?ned on an outer surface (411) of the adjusting ring (4).